In recent years, green environmental protection consciousness is raised, and many countries in the world are devoted to look for and develop an alternative energy. Since transportation is an important point in this area, many car companies have developed different types of alternative energy methods for saving energy resources. For example, a mixed power system applied with electrical energy and hydrogen energy, and a power system applied with only electrical energy. However, very few companies can achieve its target with a power system applied with mechanical energy. It is desirable that, a power system applied with mechanical energy can be operated with low energy consumption, low pollution and high efficiency.